Temblor shakes China's big dam ambitions
By Antoaneta Bezlova
DUJIANGYAN, Sichuan - China's deadly earthquake last month appears to have
shifted more than just tectonic plates in the country's picturesque Sichuan
province. The May 12 temblor has given a boost to China's green lobby, which
has been calling for a review of Beijing's zealous dam-building program and may
tilt the balance of public opinion in favor of such appeals.
When the quake struck, it came in an area famous for ancient hydrological
works. Sichuan is the homeland of Da Yu, the legendary Chinese emperor who won
his right to the throne in 21st century BCE (Before the Common, Christian
Era)by controlling floods. Instead of building dikes as others did before him,
Yu dredged out river channels to release the torrential
waters. He then directed the water to irrigate distant farm lands.
Twenty centuries later, Yu's flood controlling technique was used in the
hydraulic project of Dujiangyan. The ancient system - operational now for the
past 2,000 years - has made the city of the same name a magnet for tourists and
has won it recognition as a United Nations Educational, Scientific and Cultural
Organization World Heritage Site.
While the city of Dujiangyan was almost entirely destroyed by the magnitude
eight earthquake, the old hydraulic system located only 10 kilometers from the
epicenter, survived the temblor with little damage. The same cannot be said
about the cluster of 6,000 reservoirs and dams that local experts estimate have
been built on the rivers of Sichuan.
"Such a strong earthquake would have an enormous influence on the dams in the
whole area," says David Simpson, a US seismologist with the Incorporated
Research Institutions for Seismology. "You are certain to have concerns if you
build many dams in mountainous areas as is the case in Sichuan."
In the wake of the quake, which to date is estimated to have claimed about
70,000 lives, the rush and struggle to assess the damage done to Sichuan's
hydropower works were featured less prominently by the media than the frenzy of
rescue operations. But as provincial authorities brace for the surge of
seasonal floods, the danger of dams bursting and creating a much bigger havoc
than the earthquake has prompted Chinese experts and activists to raise their
voices.
An open letter issued by a group of 40 academics and environmentalists on June
19 warned of more devastation if environmental and geological risks of damaged
dams are disregarded. "The quake has highlighted the urgency to make a thorough
investigation of damage to the dams, which would embrace another severe test of
imminent floods,'' the petition said.
About 2,380 reservoirs and dams all over the country sustained damage from the
quake, according to a Ministry of Water Resources survey last month. Some 69
were assessed to be on the verge of collapse. But experts say this is only an
indication of the total risk.
Modern China did not follow the path of its ancient sages in using rivers'
natural flows to control flooding and irrigate the land. The late communist
chairman Mao Zedong decreed that China's new socialist man must conquer nature.
In less than 60 years since the founding of communist China, the country
managed to build some 87,000 reservoirs and dams.
Over 20,000 of these are significantly high to be considered large dams.
Whether in terms of numbers or grandness of dam works, China now is the world's
leader. It is home to the Three Gorges Dam, a hydroelectric power project on
the Yangtze River which in the course of construction displayed more than 1
million people.
The country's leadership is not stopping here. More than 30 large dams are on
the drawing boards of Chinese engineers awaiting approval and completion as the
country scrambles to feed energy to its fast-growing economy.
Initial official statements after the quake indicated little wavering from
Beijing's determination to press on with intensive hydropower development in
the area.
"There will be risk assessments of future projects in China's southwest but I
don't think the quake would lead to great changes in current plans," Liu Ning,
chief engineer with the Ministry of Water Resources told the press soon after
the earthquake.
Having harnessed major rivers and tributaries in the country's central and
eastern parts, the attention of Chinese planners is now focused on developing
the abundant water resources of western and southern provinces. But that water
cache comes with a snag - the southwestern part of China is one of the most
earthquake-prone zones in the country.
Three major fault lines traverse Sichuan, making it geologically unstable.
Nevertheless many big dams had already been built in the area, such as those on
the Min, Dadu, Jinsha and Yalu rivers. The Min, a tributary of the Yangtze that
runs right through the earthquake zone, has not less than 29 reservoirs and
dams.
What is more, Zipingpu, the Min river's largest dam sits only 5.5 kilometers
from the epicenter of the earthquake. Fan Xiao, a geologist based in Sichuan,
believes the construction of Zipingpu has contributed to the severity of the
latest earthquake.
"There has never been such a strong earthquake in this area before," Fan says.
"Our records show four earthquakes in the past of magnitude above six but never
one stronger than this latest one. Zipingpu is the biggest dam on the
Longmenshan fault line and it was filled sometime ago - in the end of 2006. We
need to investigate the possibility that the dam was among the triggers of the
quake."
Sichuan Seismological Bureau, which from the very beginning opposed the
construction of the dam because of its proximity to the Longmenshan fault line,
is now investigating the likelihood that the dam could have exacerbated the
severity of the tremor. "We hope the results of the investigation will be made
public," says Fan.
Four major earthquakes in the past are acknowledged to have been triggered by
dams in their vicinities - in Koyna, India (1967), Kremasta, Greece (1965), in
Kariba, Zimbabwe-Zambia (1961) and in Xinfengjiang, China (1962). China's quake
measured 6.1 and damaged the Xinfengjiang power station in Guangdong to such
extent that it led to its closure.
While Zipingpu in Sichuan was built to the highest quake-resistant standards,
many other Chinese dams, particularly those designed and constructed during the
Great Leap Forward (1958-1961) and in the 1960s are not. They are often
referred to by experts here as "time bombs". A history of China's half-century
of dam building, compiled by academic Pan Jiazheng, estimates there are 30,000
of these poorly built and obsolete structures all over the country.
The May 12 tremor caused the quake-proof Zipingpu Dam to sustain severe cracks
and fractures on the sides but the damage done to other older and less
quake-resistant dams is anybody's guess.
The open letter issued by China's green lobby appeals not just for thorough
investigation into the quake damage but also for risk assessments of all
hydropower projects planned for earthquake-prone Sichuan and Yunnan provinces.
A series of 13 dams, many of them taller than the 150 meter-high Zipingpu, are
projected to be built on the Nu River, in proximity to another major fault line
near China's border with Myanmar and Laos.
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